Data transformation (first draft)

dabrze · dabrze · commit 329009b93df5 · 2015-10-16T23:13:01.000+02:00
diff --git a/Przetwarzanie_danych/MANIFEST b/Przetwarzanie_danych/MANIFEST
@@ -0,0 +1,4 @@
+Transformowanie_danych_(dplyr)
+Grupowanie_danych_(dplyr)
+Czyszczenie_danych_(tidyr)
+Obsluga_dat_(lubridate)
diff --git a/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/2014-07-08.csv b/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/2014-07-08.csv
diff --git a/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/customTests.R b/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/customTests.R
@@ -0,0 +1,50 @@
+# Turn off double evaluation to make things faster
+AUTO_DETECT_NEWVAR <- FALSE
+
+match_call <- function(correct_call = NULL) {
+  e <- get("e", parent.frame())
+  # Trivial case
+  if(is.null(correct_call)) return(TRUE)
+  # Get full correct call
+  full_correct_call <- expand_call(correct_call)  
+  # Expand user's expression
+  expr <- deparse(e$expr)
+  full_user_expr <- expand_call(expr)
+  # Compare function calls with full arg names
+  identical(full_correct_call, full_user_expr)
+}
+
+# Utility function for match_call answer test
+# Fills out a function call with full argument names
+expand_call <- function(call_string) {
+  # Quote expression
+  qcall <- parse(text=call_string)[[1]]
+  # If expression is not greater than length 1...
+  if(length(qcall) <= 1) return(qcall)
+  # See if it's an assignment
+  is_assign <- is(qcall, "<-")
+  # If assignment, process righthandside
+  if(is_assign) {
+    # Get righthand side
+    rhs <- qcall[[3]]
+    # If righthand side is not a call, can't use match.fun()
+    if(!is.call(rhs)) return(qcall)
+    # Get function from function name
+    fun <- match.fun(rhs[[1]])
+    # match.call() does not support primitive functions
+    if(is.primitive(fun)) return(qcall)
+    # Get expanded call
+    full_rhs <- match.call(fun, rhs)
+    # Full call
+    qcall[[3]] <- full_rhs
+  } else { # If not assignment, process whole thing
+    # Get function from function name
+    fun <- match.fun(qcall[[1]])
+    # match.call() does not support primitive functions
+    if(is.primitive(fun)) return(qcall)
+    # Full call
+    qcall <- match.call(fun, qcall)
+  } 
+  # Return expanded function call
+  qcall
+}
diff --git a/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/dependson.txt b/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/dependson.txt
@@ -0,0 +1 @@
+dplyr
diff --git a/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/initLesson.R b/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/initLesson.R
@@ -0,0 +1,21 @@
+### Code used to download and save data
+# logurl <- 'http://cran-logs.rstudio.com/2014/2014-07-08.csv.gz'
+# filepath <- paste0('~/', basename(logurl))
+# download.file(logurl, filepath)
+# cranlog <- read.csv(filepath)
+# write.csv(cranlog, 'Getting_and_Cleaning_Data/Manipulating_Data_with_dplyr/2014-07-08.csv')
+# unlink(filepath)
+
+# Make path to csv available to user
+path2csv <- file.path(path.package('swirl.pl'), 'Courses',
+                      'Przetwarzanie_danych',
+                      'Transformowanie_danych_(dplyr)',
+                      '2014-07-08.csv')
+
+# Create datasets for user. We don't advertise that we're
+# doing this, but it will be necessary for students who
+# quit and later resume. We are not saving the variable
+# to the progress file to save on performance.
+cran <- tbl_df(read.csv(path2csv, stringsAsFactors = FALSE))
+cran2 <- select(cran, size:ip_id)
+cran3 <- select(cran, ip_id, package, size)
diff --git a/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/lesson.yaml b/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/lesson.yaml
diff --git a/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/outline.R b/Przetwarzanie_danych/Transformowanie_danych_(dplyr)/outline.R
@@ -0,0 +1,52 @@
+### Manipulating data with dplyr - Getting and Cleaning Data ###
+
+# Code to download data
+# logurl <- 'http://cran-logs.rstudio.com/2014/2014-07-08.csv.gz'
+# filepath <- paste0('~/', basename(logurl))
+# download.file(logurl, filepath)
+# cranlog <- read.csv(filepath)
+# write.csv(cranlog, '~/Desktop/2014-07-08.csv')
+# unlink(filepath)
+
+path2csv <- file.path('~/Desktop/2014-07-08.csv')
+
+
+### Intro
+df <- read.csv(path2csv, as.is = TRUE)
+dim(df)
+head(df)
+library(dplyr)
+cran <- tbl_df(df)
+cran
+?manip
+
+# "The dplyr philosophy is to have small functions that each do
+# one thing well."
+
+
+### select()
+select(cran, ip_id, package, country) # reorders
+select(cran, r_arch:country)
+select(cran, -(X:time))
+select(cran, ip_id:size)
+
+### filter()
+filter(cran, package == "swirl")
+filter(cran, r_version == "3.1.1", country == "US")
+filter(cran, country == "US" | country == "CA")
+filter(cran, r_version >= "3.0.0", r_os == "linux-gnu")
+filter(cran, !is.na(package))
+
+### arrange()
+arrange(cran, ip_id)
+arrange(cran, package, ip_id)
+arrange(cran, country, desc(r_version), ip_id)
+arrange(cran, package, desc(version), ip_id)
+
+### mutate()
+cran1 <- select(cran, ip_id, package, size)
+mutate(cran1, size_mb = size / 2^20)
+mutate(cran1, size_mb = size / 2^20, size_gb = size_mb / 2^10)
+
+### summarize()
+summarize(cran, avg_bytes = mean(size))
